Method of refining oils and fats.



. No Drawing.

ods of puri UNITED STATES PATENT OFFICE.

OTTO G. HAG-EMANN, OF YONIIERS, NEW YORK, ASSIGNOR T0 CONRAD A. DIETERICH, OF MOUNT VERNON, NEW YORK.

' METHOD OF REFINING OILS AND FATS.

To all whom it may concern:

Be it known that I, O'r'ro C. HAGEnIANN, a subject of the King of Great Britaln, r esiding at Yonkers, Westchester county, in the State of New York, have invented certain new and useful Im rovements in Methods of Refining Oils an Fats, of which the following is a specification.

My invention relates to improvements 1n the treatment of fats and oils, and the same has for its object more particularly to provide a simple, eflicient and economic method of purifying fats'and oils by means of which the same may be more thoroughly purified, a higher degree of refining attained, and the refining losses greatly reduced.

To the attainment of the aforesaid objects and ends my invention consists in the successive steps, constituting my method, as hereinafter more fully described, and then pointed out in the claims.

In the usual and generally ractised methcaustic alkalis, an excess of the latter over and above the stoicheiometric requirements of any free fatty acids present, as well as above the amounts enteringinto combination with albuminous and colorin matters,

has to be employed in order to lnsure the sufiicient removal of the impurities. In consequence hereof an undesirablylarge amount of. soap is formed as the caustic alkali attacks some of the neutral fat as well. This result is produced more particularly because of the more or less elevated temperatures at which the protracted refining oper ations are carried on. During these oper-" ations the fats and oils remain in intimate contact for a long time with the excessive amount of caustic alkali employed. In order to keep down this refining loss, chemists seek to work with the minimum amount of caustic soda capable of producing asuflicient degree of purification. This practice is followed although well aware that, when viewed from the discolorizing standpoint, a more liberal excess of caustic soda is de sirable in order toefl'ect a speedy and thorough purification.

Now I have found an eificient and convenient means for arresting the caustic action in the mixture of oil, soapy albuminous, and coloring impurities at the moment when discolorization of the fat or oil is completed, and thusprotect thepure oil Specification of Letters Patent.

' found, however,

fymg fats and oi s by means of Patented July 20, 1915.

Application filed November 4, 1913. Serial No. 799,100.

the process of purifying has advanced to this stage I add to the mixture of caustic alkali and fats, a suflicient quantity of carbonic acid, alkaline bicarbonate, boric acid or any other suitable acid or acid salt which will serve to reduce the causticity. I have that the acid or acid salt employed must be of such a character as will not interfere with the previous purifying action of the caustic alkali, and as will not appreciably reverse saponification. By the addition of carbonic acid, alkaline bicarbonate, boric acid or other acid or acid salt to the mixture of caustic alkali and fat the free caustic alkali promptly becomes converted into carbonate jar, borate which is incapable of saponifying'the neutral fats no matter how much further the operationsincidental to oil refining viz,- mixing, settling and separating,-may be continued.

In carrying out my invention I proceed as follows: After the mixture of fat or oil and caustic alkali has been agitated and a sufiicient degree of discolorization attained,

I add thereto such an amount of alkaline bicarbonate, suitably mixed with water, as will convert practically all the uncombined caustic alkali into carbonate. Or I may in corporate carbonic acid (gas) with the mixture until the same result is attained.

As is well known the absolute or specific proportion of caustic alkalis required for certain fats may vary very greatly, but the quantity required in any instance may be readily determined by the chemist since he has convenient means for determining the amounts of uncombined caustic alkalis pres ent, as, for exmaple, by shaking a sample of free alkali, the quantity of carbonic mav be calculated.

By reason of my improved process greater excesses of caustic alkali may be employed in oil refining, and a higher degree of refining attained, and at the same time the ref fining losses greatly reduced as the time durg which the fats are treated with caustic liquors is materially shortened.

' I am well aware that bicarbonate of soda has heretofore been used in producing neutral soaps. In such cases, as a first step. all the fat or oil present in the mixture had acid or bicarbonate or by a preliminary refining test been saponified by boiling with an excess of caustic soda, and such excess then neutralized with bicarbonate in order to render the soap less harsh and caustic. My invention however is distinct therefrom and relates to the entirely different and far reaching technical effect of preventing losses in oil and fat purification by protecting the fiat against unnecessary and undesirable saponification, and of insuring a more perfect or greater degree of refining by rendering possible the use of increased excesses of caustic alkalis in refining operations over and above those now employed.

tying action of said alkali is completed, by

amaeea neutralizing the further action of said caustic alkali by means ofa Weak acid, substantially as specified.

2. The method of refining oils and fats which consists in subjecting the same to the action of a caustic alkali, and then reducing the causticity of the mixture after the purifying action of said alkali is completed, by neutralizing the further action of said caustic alkali by means of a weak acid which does not possess the property of appreciably reversing saponification, substantially as specified;

Signed at the city of New York, in the county and State of New York, this 9th day of October, one thousand nine hundred and thirteen.

CONRAD A. Dm'rERioH, JOSEPH Gr. QUINN, Jr. 

